1198117491 has 4 divisors (see below), whose sum is σ = 1597489992. Its totient is φ = 798744992.

The previous prime is 1198117489. The next prime is 1198117499. The reversal of 1198117491 is 1947118911.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1198117491 - 2¹ = 1198117489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1198117499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199686246 + ... + 199686251.

It is an arithmetic number, because the mean of its divisors is an integer number (399372498).

Almost surely, 2^1198117491 is an apocalyptic number.

1198117491 is a deficient number, since it is larger than the sum of its proper divisors (399372501).

1198117491 is an equidigital number, since it uses as much as digits as its factorization.

1198117491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399372500.

The product of its digits is 18144, while the sum is 42.

The square root of 1198117491 is about 34613.8338096201. The cubic root of 1198117491 is about 1062.1025938176.

The spelling of 1198117491 in words is "one billion, one hundred ninety-eight million, one hundred seventeen thousand, four hundred ninety-one".